1. Field of the Invention
This invention relates to rotary cylindrical ironers comprising concentric cylinders having a cylindrical passageway through which a heated liquid passes. More particularly, this invention pertains to a liquid-tight joint adapted for use between the ends of the cylinders of such ironers.
2. Description of the Prior Art
The use of a heated fluid passing through the inner cylindrical passageway of a jacketed rotary cylindrical ironer is well known in the art. Thus Sullivan U.S. Pat. No. 2,322,957 discloses a direct fired flatwork ironer having such cylindrical passageways in which the fluid medium passing between concentric cylinders defining such passageway is heated by direct flame infringement against the inner periphery of the inner cylinder of such ironer.
Kroon U.S. Pat. No. 3,169,050 is directed to a rotary drying drum having a shell through which a heating fluid is circulated. Such dryer employs pivotally connected links for permitting movement of the inner cylinder relative to an outer drum. Such movement is necessitated by heat expansion in the normal course of operation. Replaceable packing effects seals at drum ends which define the limits of a cylindrical passageway through which a fluid heating medium circulates.
Lockhart U.S. Pat. No. 3,331,434 is directed to a jacketed heat transfer roll employing a thermal liquid. The Lockhart roll rotates with its own reservoir of liquid, is internally heated and relies upon centrifugal force to distribute heated liquid through the roll jacket and assist in maintaining desired uniformity of roll temperature.
Kamberg U.S. Pat. No. 4,485,573 discloses an internally heated, jacketed ironing roll employing concentric cylinders, but does not suggest any means for contending with differences in such cylinder expansion in the normal course of roll operation.
The prior art is thus seen to be familiar with rotary drying rolls comprising concentric cylinders defining a passageway through which a fluid medium passes. The prior art also discloses such a jacketed cylinder which is internally heated by direct flame infringement. As the inner cylinder is first heated, it will expand relative to the spaced-apart outer cylinder. It is therefore necessary that seals be present at the cylinder ends which may cope with differences in cylinder expansion without leakage of the heating medium passing between the cylinders. However, the prior art fails to disclose or suggest a simple and effective joint between the ends of such heated concentric cylinders which is fluid-tight and easily manufactured and maintained.
It is an object of this invention therefore to provide a jacketed ironing roll construction which employs an expansion joint formed from pipe in the form of a toroidal segment which is welded between the ends of concentric cylinders.
It is another object of this invention to provide an expansion joint for use with a jacketed cylinder of an ironing apparatus which is rugged and durable although composed of a minimum of simple elements.
It is a further object of this invention to provide a modified expansion joint construction for use with an internally heated jacketed cylinder of an ironing roll employing an inner cylinder jacket having a converging end portion. The latter is in combination with a chamber-defining end ring welded between the ends of concentric cylinders of such ironing roll as will hereinafter be explained in greater detail.
The above and other objects of this invention will become apparent from the following detailed description when read in the light of the drawing and appended claims.